[PATCH 2/3] nvme-core: don't check non-mdts for disc ctrl

[Chaitanya Kulkarni]

On 4/11/22 03:49, Chaitanya Kulkarni wrote:
>>> I think we can skip the whole call to nvme_init_non_mdts_limits in this
>>> case.  And we should probably key it off having I/O queues to also
>>> cover administrative controllers.
>>
>> I'd also move this check to the call-site instead of where it is now.
> 
> Okay, I'll add it to V2.
> 
> -ck
> 
> 

Instead of checking for the I/O queues, we already set n cache the 
mandatory field cntrltype in the nvme_ctrl, how about we use that ?

nvme (nvme-5.18) # cat 
0001-nvme-core-check-non-mdts-only-for-I-O-ctrl.patch
 From 93914f9ed43e7974294dc815ce6ed68c99044f16 Mon Sep 17 00:00:00 2001
From: Chaitanya Kulkarni <kch at nvidia.com>
Date: Fri, 8 Apr 2022 15:50:10 -0700
Subject: [PATCH] nvme-core: check non-mdts only for I/O ctrl

Validate the controller type is NVME_CTRL_IO before checking the
non mdts limits, as we don't support I/O command set for discovery and
admin ctrl, this also masks the following warning reported by the
nvme_log_error() when running blktest nvme/002: -

[ 2005.155946] run blktests nvme/002 at 2022-04-09 16:57:47
[ 2005.192223] loop: module loaded
[ 2005.196429] nvmet: adding nsid 1 to subsystem blktests-subsystem-0
[ 2005.200334] nvmet: adding nsid 1 to subsystem blktests-subsystem-1

<------------------------------SNIP---------------------------------->

[ 2008.958108] nvmet: adding nsid 1 to subsystem blktests-subsystem-997
[ 2008.962082] nvmet: adding nsid 1 to subsystem blktests-subsystem-998
[ 2008.966102] nvmet: adding nsid 1 to subsystem blktests-subsystem-999
[ 2008.973132] nvmet: creating discovery controller 1 for subsystem 
nqn.2014-08.org.nvmexpress.discovery for NQN testhostnqn.
*[ 2008.973196] nvme1: Identify(0x6), Invalid Field in Command (sct 0x0 
/ sc 0x2) MORE DNR*
[ 2008.974595] nvme nvme1: new ctrl: "nqn.2014-08.org.nvmexpress.discovery"
[ 2009.103248] nvme nvme1: Removing ctrl: NQN 
"nqn.2014-08.org.nvmexpress.discovery"

Signed-off-by: Chaitanya Kulkarni <kch at nvidia.com>
---
  drivers/nvme/host/core.c | 8 +++++---
  1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/drivers/nvme/host/core.c b/drivers/nvme/host/core.c
index e8d6a1e52083..913eb4cec048 100644
--- a/drivers/nvme/host/core.c
+++ b/drivers/nvme/host/core.c
@@ -3101,9 +3101,11 @@ int nvme_init_ctrl_finish(struct nvme_ctrl *ctrl)
  	if (ret)
  		return ret;

-	ret = nvme_init_non_mdts_limits(ctrl);
-	if (ret < 0)
-		return ret;
+	if (ctrl->cntrltype == NVME_CTRL_IO) {
+		ret = nvme_init_non_mdts_limits(ctrl);
+		if (ret < 0)
+			return ret;
+	}

  	ret = nvme_configure_apst(ctrl);
  	if (ret < 0)
-- 
2.29.0